Future nuclear weapon policies
James M. Acton
jacton@ceip.org
(Some) elements of nuclear posture
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Force size and structure
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Military Organization
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Warhead production/maintenance facilities; industrial base; test facilities
Declaratory policy
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Command and control; early warning; ISR; targeting
Infrastructure
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Troops; training; procedures; operations
Enabling systems
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Deployed and reserve systems; readiness status
Statements; training and exercises; domestic discourse
War plans
Treaty obligations
Questions raised by reductions
• Can U.S. fulfill “deterrence” requirements?
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Will weapons reach target?
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Will weapons destroy target?
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Reliability; pre- and post-launch survivability
Yield, accuracy and target location error
Can requirements be revised?
How will allies/adversaries view U.S. resolve and capability?
What will the effects on “strategic stability” be?
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Current U.S. force structure
Platform
Missile
Warhead
ICBM
(Silo based)
Minuteman III
W78; W87
SLBM
Ohio-class SSBN
Trident-D5
W76-0/1; W88
Heavy Bombers
B-2
(Gravity bombs)
B61-7/11; B83-1
B-52H
ALCM
W80-1
(+ gravity bombs)
F-15E; F-16C/D
(Gravity bombs)
B61-3/4/10
“Tactical” fighters
Future of the triad
• Political context crucial; in practice force structure will be
determined by politics of the moment as much as nuclear
strategy
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ICBM replacement will probably be delayed further (beyond
2020); early abandonment very unlikely (jobs!)
Very strong support for SLBMs
Multiple decision points related to heavy bombers and tactical
fighters coming up
• Air leg most vulnerable
Arguments for heavy bombers
and tactical fighters
• Unique ability to hold buried targets at risk
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But, how much do these targets really matter?
• Stealth as alternative to speed for defense penetration
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But, how likely is effective BMD?
• Recallable
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But, how many war plan options include only aircraft?
• Forward deployment as tool for assurance
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But, are there alternatives?
• Signaling as tool for crisis management
A growing role for conventional weapons in
strategic war plans?
DoD is directed to conduct deliberate planning for non-nuclear strike
options to assess what objectives and effects could be achieved
through integrated non-nuclear strike options, and to propose possible
means to make these objectives and effects achievable. Although they
are not a substitute for nuclear weapons, planning for non-nuclear
strike options is a central part of reducing the role of nuclear weapons.
Report on Nuclear Employment Strategy of the United States (2013)
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Probably not about large-scale replacement.
Types of target in a “counterforce” attack
against North Korea
• Fixed, soft targets
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ICBM sitting on a launch pad
• Fixed, buried targets
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Warhead storage facilities; leadership; command and control
Probably tens, potentially hundreds of metres deep
• Mobile, soft targets
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Road-mobile missiles
Massive ordnance penetrator
• Total mass: 13,600 kg
• HE mass: 2,400 kg
• Can reportedly
penetrate to 20 m in
reinforced concrete
(much less than
nuclear weapons)
Physics of conventional penetrators
Young Penetration Equation (SI Units)
𝑚
𝐷 = 0.000018 𝑆 𝑁
𝐴
0.7
𝑉 − 30.5
D: Depth
S: Penetrability of target
N: Nose performance coefficient
m: Mass
A: Cross sectional area
V: Speed
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From Nelson (2002)
CPGS technological approaches
Comparison of penetrator effectiveness
𝑚
𝐷 = 0.000018 𝑆 𝑁
𝐴
0.7
𝑉 − 30.5
MOP
CPGS
V (m/s)
500 [?]
1,000-1,200
m/A (kg/m)
27,000
14,000-21,000
• Ratio of penetration depths: 1.3-2.1
• CPGS penetrator would only contain about 10% of
the HE that MOP does.
Mobile missile hunting
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Need to locate and track missiles
If using standoff weapons need to provide inflight target updates
(or risk waiting until they’re stationary)
North Korea has hundreds of mobile ballistic missiles
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Only a small fraction might contain a nuclear warhead, but very hard to tell
which is which
1991 Gulf War: 1,460 sorties; 0 confirmed kills
2006 Israel-Hizbollah war: 80-90% of Hizbollah’s medium- and longrange rocket launchers destroyed. But, took time and relied on
attacking launchers after missiles has fired.
Nuclear v. conventional options
• Lethal radius from flechette weapon: <100 m, possibly
much less (my calculation)
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TEL can traverse this distance in 10 s
• Lethal radius from 100 kT nuclear weapon: 2,900 m
(McKinzie et al. 2001)
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TEL can traverse this distance in 260 s
• Hunting mobile missiles with conventional weapons much
harder than nuclear weapons